In recent years, with the spread of large-volume content service, there has been a demand for a significant improvement in transmission speed (throughput). For example, in LTE-Advanced (LTE-A) standardized by Third Generation Partnership Project (3GPP), for example, a multi-input multi-output (MIMO) system is used as a technique corresponding to the demand.
In the MIMO system, high-speed data communication is performed by M×N paths formed between a plurality of (M) transmitter-side antennas and a plurality of (N) receiver-side antennas.
As such, in a communication system which transmits and receives a plurality of different signals at the same time, a signal analysis device is used to evaluate the quality of a transmitter-side signal.
As the signal analysis device, a device has been known which three-dimensionally displays, as a parameter, the size of each frequency component obtained by analysis on a coordinate system in which the frequency (received frequency) to be analyzed is one coordinate axis and the analysis time (received time) is the other coordinate axis (for example, see Patent Documents 1 and 2).